Hungarian biochemist and pioneer of messenger RNA technology. Her research, long overlooked, made mRNA vaccines against COVID-19 possible. She received the Nobel Prize in Physiology or Medicine in 2023.
Katalin Karikó(1955 — ?)
Katalin Karikó
Hongrie, États-Unis
8 min read
Frequently asked questions
Key Facts
- Born in 1955 in Hungary, she emigrated to the United States in 1985 to pursue her research
- For decades, her work on messenger RNA was ignored and underfunded
- In 2005, she published a landmark discovery with Drew Weissman showing that mRNA could be used without triggering an excessive immune response
- Her work enabled the development of the Pfizer-BioNTech and Moderna COVID-19 vaccines in 2020
- She received the Nobel Prize in Physiology or Medicine in 2023 alongside Drew Weissman
Works & Achievements
Paper co-authored with Drew Weissman demonstrating that chemically modified nucleosides allow mRNA to evade recognition as foreign by the immune system. Considered the scientific breakthrough that made mRNA vaccines possible.
First patent filed by Karikó and Weissman protecting the mRNA modification technology. It was later licensed to Moderna and BioNTech, becoming the cornerstone of an entire industry.
Second major publication clarifying that pseudouridine (a modified base) increases both the stability and translation efficiency of mRNA while reducing its immunogenicity.
The first mRNA vaccine granted emergency authorization worldwide, developed in under a year at BioNTech with Karikó's direct contribution. It relies entirely on the modified nucleoside technology she pioneered.
A memoir in which Karikó recounts her journey from communist Hungary to American laboratories, the repeated rejections, the demotion, and the perseverance that ultimately led her to the Nobel Prize.
Anecdotes
In 1985, Katalin Karikó and her husband decided to leave Hungary for the United States to pursue her research. Unable to freely take their money out of the country, they converted the proceeds from selling their car (roughly 900 British pounds) into dollars, which they hid inside their little daughter Susan's teddy bear. That child would later become a two-time Olympic rowing champion.
In 1995, her supervisor at the University of Pennsylvania lost faith in her work on messenger RNA and demoted her, stripping her of her faculty position and funding. Rather than giving up, Karikó continued her research on a reduced salary, convinced that therapeutic mRNA was achievable. That perseverance would ultimately change the history of medicine.
It was at a photocopier that Katalin Karikó met immunologist Drew Weissman around 1997. As they discussed their respective work, they realized they could combine their expertise. From that chance encounter grew the scientific collaboration that would lead to the discovery of modified nucleosides and, twenty years later, to the Nobel Prize.
Their 2005 paper in the journal Immunity, describing how to modify messenger RNA so it would no longer trigger an inflammatory response in human cells, was initially rejected by the leading journals Nature and Science. Ignored for years by the scientific community, this work is now recognized as one of the most important biological discoveries of the twenty-first century.
When the COVID-19 pandemic broke out in 2020, Karikó had been working at BioNTech in Mainz since 2013. In less than a year, the technology she had developed over three decades of obscurity enabled the creation of the Pfizer-BioNTech BNT162b2 vaccine, administered to hundreds of millions of people around the world.
Primary Sources
We show that RNA synthesized in vitro is immunostimulatory and that this property can be reduced by the incorporation of modified nucleosides. These findings suggest a general mechanism by which modified nucleosides reduce the immunogenicity of RNA.
mRNA containing pseudouridine was translated more efficiently than unmodified mRNA in primary cells and in vivo, and was significantly less immunogenic, demonstrating its potential as a therapeutic vector.
Throughout my career I experienced many setbacks, grant rejections, and a demotion. Despite these obstacles, I never lost faith in the potential of mRNA. The discovery of modified nucleosides opened the door to safe and effective mRNA therapeutics.
Science is not a straight road. It is full of detours, failures and moments of doubt. What keeps you going is the conviction that the question you are asking matters, even when no one else believes it yet.
Key Places
A small town on the Hungarian Great Plain where Katalin Karikó was born in 1955 and grew up. Her childhood in these modest surroundings shaped her work ethic and determination.
A university city in southern Hungary where Karikó earned her doctorate in biochemistry in 1978 and began her first RNA research at the Biological Research Centre.
The institution where Karikó spent the bulk of her American career (1989–2013), despite being demoted in 1995. It was here that she met Drew Weissman and published their landmark 2005 discovery.
The biotechnology company co-founded by Uğur Şahin and Özlem Türeci that Karikó joined in 2013. It was in its laboratories that the BNT162b2 vaccine against COVID-19 was designed and developed.
On December 10, 2023, Katalin Karikó received the Nobel Prize in Physiology or Medicine in Stockholm — international recognition of thirty years of research that had been overlooked and misunderstood.
Typical Objects
Everyday tools of the biochemistry laboratory where Karikó synthesized and purified her mRNA molecules. The centrifuge separates cellular components to isolate and analyze nucleic acids.
A precision instrument essential for handling very small volumes of liquid in molecular biology. Karikó used it for decades in her experiments on mRNA.
A machine that reads the sequence of nitrogenous bases in an RNA molecule. Essential for verifying the structure of the synthetic molecules designed by Karikó and Weissman.
A handwritten record in which researchers document each experiment, result, and hypothesis. These notebooks form the scientific and legal memory of a discovery.
A three-dimensional representation of the messenger RNA molecule, showing the single strand, the nitrogenous bases, and the protective cap. Used to visualize and explain the modifications introduced by Karikó.
A concrete symbol of the culmination of Karikó's work: hundreds of millions of syringes containing the Pfizer-BioNTech mRNA vaccine were administered worldwide between 2021 and 2023.
School Curriculum
Vocabulary & Tags
Key Vocabulary
Tags
Daily Life
Morning
Karikó arrives early at the University of Pennsylvania laboratory, often before 7 a.m. She prepares her buffer solutions, checks the previous day's cell cultures, and plans the day's experiments in her lab notebook. Mornings are dedicated to the most delicate manipulations, which require concentration and calm.
Afternoon
The afternoon is devoted to reading electrophoresis and sequencing results, drafting protocols, and often reviewing scientific articles in preparation for the next funding applications — which are regularly rejected. She also uses these hours for informal conversations with colleagues in the hallways.
Evening
In the evening, Karikó returns home to her family, sometimes late. During the years when her daughter Susan is training for rowing, they share simple evenings around a traditional Hungarian meal. She often spends part of the evening reading scientific articles or proofreading manuscripts.
Food
Karikó holds on to the eating habits of her Hungarian childhood: slow-cooked dishes, paprika, country bread. In the United States, her lifestyle remains modest; she prepares her meals at home and avoids expensive restaurants, in keeping with her salary as a demoted researcher.
Clothing
In the laboratory, she wears the standard white lab coat, nitrile gloves, and safety goggles. Outside the lab, she dresses simply and practically, with no particular concern for style. At official ceremonies such as the 2023 Nobel Prize presentation, she opts for an elegant but understated outfit.
Housing
For most of her career in Philadelphia, Karikó lives with her family in a middle-class home, far from the perks enjoyed by tenured professors. After joining BioNTech in Germany in 2013, she splits her time between Mainz and the United States, leading the life of a scientific expatriate without ostentation.
Historical Timeline
Period Vocabulary
Visual Style
Esthétique visuelle qui alterne entre le laboratoire universitaire austère des années 1990 et les installations high-tech de BioNTech, avec des représentations moléculaires colorées de l'ARNm en contraste.
Sound Ambience
Ambiance sonore d'un laboratoire de biochimie universitaire américain des années 1990–2000 : centrifugeuses, hottes à flux laminaire, pipettes et silence concentré de la recherche fondamentale.
Liens externes & ressources
Références
Œuvres
Article fondateur : « Suppression of RNA Recognition by Toll-like Receptors » (Immunity)
2005
Brevet sur les nucléosides modifiés pour l'ARNm thérapeutique
2006
Article : « Incorporation of pseudouridine into mRNA » (Molecular Therapy)
2008
Vaccin BNT162b2 (Pfizer-BioNTech) contre la COVID-19
2020-2021
Autobiographie : Breaking Through — My Life in Science
2023
